IF IT looks too good to be true, it probably is. Several "herbal remedies" for erectile dysfunction sold online actually contain the active ingredient from Viagra.

Michael Lamb at Arcadia University in Glenside, Pennsylvania, and colleagues purchased 10 popular "natural" uplifting remedies on the internet and tested them for the presence of sildenafil, the active ingredient in Viagra. They found the compound, or a similar synthetic drug, in seven of the 10 products – cause for concern because it can be dangerous for people with some medical conditions.

Lamb's work was presented last week at the American Academy of Forensic Sciences meeting in Washington DC.

This article appeared in print under the headline "Herbal Viagra gets a synthetic boost"

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.

If you are having a technical problem posting a comment, please contact technical support.

WASHINGTON: In his first interview since losing his 2012 White House bid, Mitt Romney likened his experience as a presidential candidate to an unpredictable and bumpy roller coaster ride.

"We were on a roller coaster, exciting and thrilling, ups and downs. But the ride ends," Romney said, according to advance excerpts of the interview set to air on "Fox News Sunday."

"And then you get off. And it's not like, 'Oh, can't we be on a roller coaster the rest of our life?' It's like, no, the ride's over."

Romney appeared with his wife Ann for the interview, the first either has given since the November 6 election that granted President Barack Obama his second term.

Ann Romney acknowledged that the transition from being surrounded by huge crowds and Secret Service agents around the clock to a far lower profile has been an "adjustment."

"We came and stepped forward to serve," she added.

"It was really quite a lot of energy and a lot of passion and a lot of people around us and all of a sudden, it was nothing.

"But the good news is, fortunately we like each other."

Romney, who has not had any major public appearances since his election loss, is set to speak in two weeks at a key conservative gathering, the Conservative Political Action Conference.

The former Massachusetts governor has been laying low since his defeat, popping up occasionally in photographs on social media sites that apparently depict him shopping or filling up his tank at the gas station.

When Senator John Kerry of Massachusetts left Congress to become secretary of state earlier this year, it opened up a race in his home state to fill his seat. Speculation swirled that Romney's oldest son Tagg might throw his hat in the ring, but he quickly ruled it out.

Romney aides have also rebuffed suggestions that his wife might consider running for the post.

The remains of what was once one of Los Angeles' most coveted neighborhoods can be seen behind a fence topped with barbed wire.

Weeds sprout through cracks along streets lined with majestic palms. Retaining walls and foundations of custom homes peek through the brush. Rusty utility lines that have wiggled their way above ground bake in the sun like scattered bones.

Two throttled-up passenger jets simultaneously take off from LAX and soar overhead, the thundering cacophony a reminder of why the community of Surfridge was forced to disappear.

Developed in the 1920s and 1930s, Surfridge was an isolated playground of the wealthy, among the last communities built on miles of sand dunes that once dominated the coast. Hollywood elites built homes here that commanded views from Palos Verdes to Malibu.

The small airfield to the east that opened in 1928 was a good place to see an air show. It would take nearly two decades for it to become the city's primary airport.

Today, Surfridge is a Los Angeles curiosity — a modern ghost town inhabited by a rare butterfly.

The El Segundo blue butterfly was near extinction when the last of Surfridge's 800 homes were removed in the early 1970s, the victim of an expanding Los Angeles International Airport.

In the decades since, the federally protected endangered species has made a comeback due to the establishment of a 200-acre butterfly preserve managed by the city. Nonnative plants were removed and native buckwheat — where the butterflies feed and lay their eggs — was reintroduced.

Now, more than 125,000 butterflies take flight each summer, unfazed by the constant thunder of jets overhead.

LAX may have wiped Surfridge off the map, but the airport has turned out to be a perfect neighbor for a growing community of butterflies.

"It's a remarkable recovery," said Richard Arnold, an entomologist who has worked as a consultant at the preserve. "But you've got to realize that insects have a remarkable reproductive capacity if their natural food source is there."

Soon there will be more. The California Coastal Commission recently approved a $3-million plan to restore portions of 48 acres at the northern end of the old subdivision. The project is part of a settlement of a lawsuit between LAX and surrounding cities over the airport's expansion plans.

Some streets, curbs, sidewalks, home foundations and utilities visible to neighboring homeowners will be removed. Six acres will be reseeded with native plants — sagebrush and goldenbush, primrose, poppies and salt grass among them — that will return this sliver of dunes back to where it was a century ago.

"They wanted us to fix what they consider to be an eyesore," airport spokeswoman Nancy Suey Castles said.

The story of Surfridge is a parable for a century's worth of urban growth destruction.

"It was paradise when I was a kid," said Duke Dukesherer, a business executive and amateur historian who has written about the area. "Everybody who sees it now asks the same question: What the hell happened here?"

A development company held a contest in 1925 to name its newest neighborhood, awarding $1,000 to a Los Angeles man who submitted "Surfridge."

"The outstanding name was (chosen) due to its brevity, euphony, ease of pronunciation…" The Times reported. "But above all because it most satisfactorily tells the story of this new wonder city."

Prospective buyers picked up brochures in downtown Los Angeles and drove to the coast, where salesmen worked out of tents. Lots went for $50 down and $20 a month for three years.

Home exteriors were required to be brick, stone or stucco — no frame structures allowed. And no one "not entirely that of the Caucasian race," according to the development's deed restrictions "except such as are in the employ of the resident owners."

In the story of how the dog came in from the cold and onto our sofas, we tend to give ourselves a little too much credit. The most common assumption is that some hunter-gatherer with a soft spot for cuteness found some wolf puppies and adopted them. Over time, these tamed wolves would have shown their prowess at hunting, so humans kept them around the campfire until they evolved into dogs. (See "How to Build a Dog.")

But when we look back at our relationship with wolves throughout history, this doesn't really make sense. For one thing, the wolf was domesticated at a time when modern humans were not very tolerant of carnivorous competitors. In fact, after modern humans arrived in Europe around 43,000 years ago, they pretty much wiped out every large carnivore that existed, including saber-toothed cats and giant hyenas. The fossil record doesn't reveal whether these large carnivores starved to death because modern humans took most of the meat or whether humans picked them off on purpose. Either way, most of the Ice Age bestiary went extinct.

The hunting hypothesis, that humans used wolves to hunt, doesn't hold up either. Humans were already successful hunters without wolves, more successful than every other large carnivore. Wolves eat a lot of meat, as much as one deer per ten wolves every day-a lot for humans to feed or compete against. And anyone who has seen wolves in a feeding frenzy knows that wolves don't like to share.

Humans have a long history of eradicating wolves, rather than trying to adopt them. Over the last few centuries, almost every culture has hunted wolves to extinction. The first written record of the wolf's persecution was in the sixth century B.C. when Solon of Athens offered a bounty for every wolf killed. The last wolf was killed in England in the 16th century under the order of Henry VII. In Scotland, the forested landscape made wolves more difficult to kill. In response, the Scots burned the forests. North American wolves were not much better off. By 1930, there was not a wolf left in the 48 contiguous states of America. (See "Wolf Wars.")

If this is a snapshot of our behavior toward wolves over the centuries, it presents one of the most perplexing problems: How was this misunderstood creature tolerated by humans long enough to evolve into the domestic dog?

The short version is that we often think of evolution as being the survival of the fittest, where the strong and the dominant survive and the soft and weak perish. But essentially, far from the survival of the leanest and meanest, the success of dogs comes down to survival of the friendliest.

Most likely, it was wolves that approached us, not the other way around, probably while they were scavenging around garbage dumps on the edge of human settlements. The wolves that were bold but aggressive would have been killed by humans, and so only the ones that were bold and friendly would have been tolerated.

Friendliness caused strange things to happen in the wolves. They started to look different. Domestication gave them splotchy coats, floppy ears, wagging tails. In only several generations, these friendly wolves would have become very distinctive from their more aggressive relatives. But the changes did not just affect their looks. Changes also happened to their psychology. These protodogs evolved the ability to read human gestures.

As dog owners, we take for granted that we can point to a ball or toy and our dog will bound off to get it. But the ability of dogs to read human gestures is remarkable. Even our closest relatives-chimpanzees and bonobos-can't read our gestures as readily as dogs can. Dogs are remarkably similar to human infants in the way they pay attention to us. This ability accounts for the extraordinary communication we have with our dogs. Some dogs are so attuned to their owners that they can read a gesture as subtle as a change in eye direction.

With this new ability, these protodogs were worth knowing. People who had dogs during a hunt would likely have had an advantage over those who didn't. Even today, tribes in Nicaragua depend on dogs to detect prey. Moose hunters in alpine regions bring home 56 percent more prey when they are accompanied by dogs. In the Congo, hunters believe they would starve without their dogs.

Dogs would also have served as a warning system, barking at hostile strangers from neighboring tribes. They could have defended their humans from predators.

And finally, though this is not a pleasant thought, when times were tough, dogs could have served as an emergency food supply. Thousands of years before refrigeration and with no crops to store, hunter-gatherers had no food reserves until the domestication of dogs. In tough times, dogs that were the least efficient hunters might have been sacrificed to save the group or the best hunting dogs. Once humans realized the usefulness of keeping dogs as an emergency food supply, it was not a huge jump to realize plants could be used in a similar way.

So, far from a benign human adopting a wolf puppy, it is more likely that a population of wolves adopted us. As the advantages of dog ownership became clear, we were as strongly affected by our relationship with them as they have been by their relationship with us. Dogs may even have been the catalyst for our civilization.

Dr. Brian Hare is the director of the Duke Canine Cognition Center and Vanessa Woods is a research scientist at Duke University. This essay is adapted from their new book, The Genius of Dogs, published by Dutton. To play science-based games to find the genius in your dog, visit www.dognition.com.

N'DJAMENA (Reuters) - Chadian soldiers in Mali have killed Mokhtar Belmokhtar, the al Qaeda commander who masterminded a bloody hostage-taking at an Algerian gas plant in January, Chad's military said on Saturday.

The death of one of the world's most wanted jihadists would be a major blow to al Qaeda in the region and to Islamist rebels already forced to flee towns they had seized in northern Mali by an offensive by French and African troops.

"On Saturday, March 2, at noon, Chadian armed forces operating in northern Mali completely destroyed a terrorist base. ... The toll included several dead terrorists, including their leader Mokhtar Belmokhtar," Chad's armed forces said in a statement read on national television.

On Friday, Chad's president, Idriss Deby, said his soldiers had killed another al Qaeda commander, Adelhamid Abou Zeid, among 40 militants who died in an operation in the same area as Saturday's assault - Mali's Adrar des Ifoghas mountains near the Algerian border.

France - which has used jet strikes against the militants' mountain hideouts - has declined to confirm the killing of either Abou Zeid or Belmokhtar.

In Washington, an Obama administration said the White House could not confirm the killing of Belmokhtar.

Analysts said the death of two of al Qaeda's most feared commanders in the Sahara desert would mark a significant blow to Mali's Islamist rebellion.

"Both men have extensive knowledge of northern Mali and parts of the broader Sahel and deep social and other connections in northern Mali, and the death of both in such a short amount of time will likely have an impact on militant operations," said Andrew Lebovich, a Dakar-based analyst who follows al Qaeda in the Islamic Maghreb (AQIM).

Anne Giudicelli, managing director of security consultancy Terrorisc, said the al Qaeda commanders' deaths - if confirmed - would temporarily disrupt the Islamist rebel network but would also raise concern over the fate of seven French hostages believed to be held by Islamists in northern Mali.

Chad is one of several African nations that have contributed forces to a French-led military intervention in Mali aimed at ridding its vast northern desert of Islamist rebels who seized the area nearly a year ago following a coup in the capital.

Western and African countries are worried that al Qaeda could use the zone to launch international attacks and strengthen ties with African Islamist groups like al Shabaab in Somalia and Boko Haram in Nigeria.

'MARLBORO MAN'

Belmokhtar, 40, who lost an eye while fighting in Afghanistan in the 1990s, claimed responsibility for the seizure of dozens of foreign hostages at the In Amenas gas plant in Algeria in January in which more than 60 people were killed.

That attack put Algeria back on the map of global jihad, 20 years after its civil war, a bloody Islamist struggle for power. It also burnished Belmokhtar's jihadi credentials by showing that al Qaeda remained a potent threat to Western interests despite U.S. forces killing Osama bin Laden in Pakistan in 2011.

Before In Amenas, some intelligence experts had assumed Algerian-born Belmokhtar had drifted away from jihad in favor of kidnapping and smuggling weapons and cigarettes in the Sahara where he earned the nickname "Marlboro Man".

In a rare interview with a Mauritanian news service in late 2011, Belmokhtar paid homage to bin Laden and his successor, Ayman al-Zawahri. He cited al Qaeda's traditional global preoccupations, including Iraq, Afghanistan and the fate of the Palestinians, and stressed the need to "attack Western and Jewish economic and military interests".

He shared command of field operations for AQIM - al Qaeda's North African franchise - with Abou Zeid, although there was talk the two did not get along and were competing for power.

A former smuggler turned jihadi, Algerian-born Abou Zeid imposed a violent form of sharia, Islamic law, in the ancient desert town of Timbuktu, including amputations and the destruction of ancient Sufi shrines.

Robert Fowler, a former Canadian diplomat held hostage by Belmokhtar from 2008 to 2009, told Reuters, "While I cannot consider reports of the death of both Abou Zeid and Mokhtar Belmokhtar as anything but good news ... I must temper my enthusiasm by the fact that this is by no means the first time Belmokhtar's death has been reported."

President Francois Hollande said on Friday that the assault to retake Mali's vast desert north from AQIM and other Islamist rebels that began on January 11 was in its final stage and so could not confirm Abou Zeid's death.

A U.S. official and a Western diplomat said, however, the reports about Abou Zeid's death appeared to be credible.

U.S. Representative Ed Royce, Republican chairman of the House Foreign Affairs Committee, said the killing of Belmokhtar "would be a hard blow to the collection of jihadists operating across the region that are targeting American diplomats and energy workers."

Washington has said it believes Islamists operating in Mali were involved in the killing of the U.S. ambassador in Libya's eastern city of Benghazi in September.

After its success in dislodging al Qaeda fighters from northern Mali's towns, France and its African allies have faced a mounting wave of suicide bombings and guerrilla-style raids by Islamists in northern Malian towns.

U.N. Secretary-General Ban Ki-moon said on Friday that a U.N. peacekeeping force to replace French troops in Mali should be discussed as soon as possible.

Chad was among the quickest to respond to Mali's appeals for help alongside the French, rushing in hundreds of troops experienced in desert warfare, led by Deby's son, General Mahamat Deby.

The country's president may be hoping to polish his regional and international credentials by assisting in this war, while bolstering his own position in power in Chad, which has been threatened in the past by eastern neighbor Sudan.

(Additional reporting by John Irish and David Lewis in Dakar, Gus Trompiz in Paris, and Mark Hosenball and Mark Felsenthal in Washington; Writing by Richard Valdmanis; Editing by Robin Pomeroy and Peter Cooney)

IF IT looks too good to be true, it probably is. Several "herbal remedies" for erectile dysfunction sold online actually contain the active ingredient from Viagra.

Michael Lamb at Arcadia University in Glenside, Pennsylvania, and colleagues purchased 10 popular "natural" uplifting remedies on the internet and tested them for the presence of sildenafil, the active ingredient in Viagra. They found the compound, or a similar synthetic drug, in seven of the 10 products – cause for concern because it can be dangerous for people with some medical conditions.

Lamb's work was presented last week at the American Academy of Forensic Sciences meeting in Washington DC.

This article appeared in print under the headline "Herbal Viagra gets a synthetic boost"

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.

If you are having a technical problem posting a comment, please contact technical support.

WASHINGTON: President Barack Obama ordered $85 billion in budget cuts Friday that could slow the US economy and slash jobs, after blaming Republicans for refusing to stop the "dumb" spending cuts.

Obama complied with his legal obligations and initiated the automatic, across-the-board cuts in domestic and defence spending, following the failure of efforts to clinch a deal with Republicans on cutting the deficit.

Nearly two-thirds of American voters believe that human population growth is driving other animal species to extinction and that if the situation gets worse, society has a "moral responsibility to address the problem," according to new national public opinion poll.

A slightly lower percentage of those polled — 59% — believes that population growth is an important environmental issue and 54% believe that stabilizing the population will help protect the environment.

The survey was conducted on behalf of the nonprofit Center for Biological Diversity, which unlike other environmental groups has targeted population growth as part of its campaign to save wildlife species from extinction.

The center has handed out more than half a million condoms at music concerts, farmers markets, churches and college campuses with labels featuring drawings of endangered species and playful, even humorous, messages such as, "Wrap with care, save the polar bear."

The organization hired a polling firm to show other environmental groups that their fears about alienating the public by bringing up population matters are overblown, said Kieran Suckling, the center's executive director. When the center broke the near-silence on population growth with its condom campaign, other environmental leaders "reacted with a mix of worry and horror that we were going to experience a huge backlash and drag them into it," he said.

Instead, Suckling said the campaign has swelled its membership — now about 500,000 — and donations and energized 5,000 volunteers who pass out prophylactics. He said a common response is, "Thank God, someone is talking about this critical issue."

The poll results, he said, show such views are mainstream.

In the survey, the pollsters explained that the world population hit 7 billion last year and is projected to reach 10 billion by the end of the century. Given those facts, 50% of people reached by telephone said they think the world population is growing too fast, while 38% said population growth was on the right pace and 4% thought it was growing too slowly. About 8% were not sure.

Sixty-one percent of respondents expressed concerned about disappearing wildlife. Depending how the question was phrased, 57% to 64% of respondents said population growth was having an adverse effect. If widespread wildlife extinctions were unavoidable without slowing human population growth, 60% agreed that society has a moral responsibility to address the problem.

Respondents didn't make as clear a connection between population and climate change, reflecting the decades-old debate over population growth versus consumption. Although 57% of respondents agreed that population growth is making climate change worse, only 46% said they think having more people will make it harder to solve, and 34% said the number of people will make no difference.

Asked about natural resources, 48% said they think the average American consumes too much. The view split sharply along party lines, with 62% of Democrats saying the average American consumes too much, compared with 29% of Republicans. Independents fell in the middle at 49%.

The survey of 657 registered voters was conducted Feb. 22-24 by Public Policy Polling, a Raleigh, N.C., firm that takes the pulse of voters for Democratic candidates and Democratic-leaning clients. It has a margin of error of 3.9%.

A superfast black hole nearly 60 million light-years away appears to be pushing the ultimate speed limit of the universe, a new study says.

For the first time, astronomers have managed to measure the rate of spin of a supermassive black hole—and it's been clocked at 84 percent of the speed of light, or the maximum allowed by the law of physics.

"The most exciting part of this finding is the ability to test the theory of general relativity in such an extreme regime, where the gravitational field is huge, and the properties of space-time around it are completely different from the standard Newtonian case," said lead author Guido Risaliti, of the Harvard-Smithsonian Center for Astrophysics (CfA) and INAF-Arcetri Observatory in Italy. (Related: "Speedy Star Found Near Black Hole May Test Einstein Theory.")

Notorious for ripping apart and swallowing stars, supermassive black holes live at the center of most galaxies, including our own Milky Way. (See black hole pictures.)

They can pack the gravitational punch of many million or even billions of suns—distorting space-time in the region around them, not even letting light to escape their clutches.

Galactic Monster

The predatory monster that lurks at the core of the relatively nearby spiral galaxy NGC 1365 is estimated to weigh in at about two million times the mass of the sun, and stretches some 2 million miles (3.2 million kilometers) across-more than eight times the distance between Earth and the moon, Risaliti said. (Also see "Black Hole Blast Biggest Ever Recorded.")

Risaliti and colleagues' unprecedented discovery was made possible thanks to the combined observations from NASA's high-energy x-ray detectors on its Nuclear Spectroscopic Telescope Array (NuSTAR) probe and the European Space Agency's low-energy, x-ray-detecting XMM-Newton space observatory.

Astronomers detected x-ray particle remnants of stars circling in a pancake-shaped accretion disk surrounding the black hole, and used this data to help determine its rate of spin.

By getting a fix on this spin speed, astronomers now hope to better understand what happens inside giant black holes as they gravitationally warp space-time around themselves.

Even more intriguing to the research team is that this discovery will shed clues to black hole's past, and the evolution of its surrounding galaxy.

Tracking the Universe's Evolution

Supermassive black holes have a large impact in the evolution of their host galaxy, where a self-regulating process occurs between the two structures.

"When more stars are formed, they throw gas into the black hole, increasing its mass, but the radiation produced by this accretion warms up the gas in the galaxy, preventing more star formation," said Risaliti.

"So the two events—black hole accretion and formation of new stars—interact with each other."

Knowing how fast black holes spin may also help shed light how the entire universe evolved. (Learn more about the origin of the universe.)

"With a knowledge of the average spin of galaxies at different ages of the universe," Risaliti said, "we could track their evolution much more precisely than we can do today."

BEIRUT (Reuters) - Syrian President Bashar al-Assad's forces seized a village southeast of the city of Aleppo on Friday, reopening a supply line to the country's biggest city where they have been battling rebels for eight months, a monitoring group said.

The Syrian Observatory for Human Rights said the capture of Tel Shghaib marked the last step to creating a land supply route north into Aleppo from Hama province, crucial for Assad's forces who have lost control of part of the main north-south highway.

Rebels say they hold most of the city itself and nearly all the rural hinterland. But they have been unable to achieve a decisive victory and complain that they are outgunned and vulnerable to Assad's air force, artillery and ballistic missiles, which killed dozens of people in Aleppo last week.

The United States pledged direct but non-lethal aid to the rebels at a meeting in Rome on Thursday, disappointing Assad's opponents who had hoped for more tangible military support to tip the balance of forces on the ground.

Activists reported another day of fierce fighting around Aleppo, including the military airport at Nairab, three miles north of Tel Shghaib which Assad's forces retook.

"It's a significant gain for the regime," the British-based Observatory's director Rami Abdelrahman said of the army's push north, which reversed many rebel advances when they moved south into Hama from Aleppo province at the end of last year.

Further east, on the Iraqi frontier, government troops also managed to wrest back control of the Yarubiyah border crossing after insurgents seized it 24 hours earlier, he said.

SYRIA COULD FALL APART

The revolt against Assad, which erupted in March 2011 with mainly peaceful protests, has escalated into civil war between mainly Sunni Muslim forces and troops and militias loyal to Assad, from the minority Alawite community whose faith derives from Shi'ite Islam.

The United Nations says 70,000 people have been killed, nearly a million have fled the country and millions more have been displaced or need aid.

U.N. Secretary-General Ban Ki-moon said on Friday that Syria, a major Arab state on the fault lines of broader Middle East conflict, would fall apart if the government and rebels keep fighting instead of seeking a negotiated peace.

"This is a very small window of opportunity which we strongly support and encourage them to use that. The opportunity may close soon," Ban said in Geneva.

The government and opposition have both edged away in recent weeks from their previous rejection of dialogue. Foreign Minister Walid al-Moualem said on Monday the government would even talk to armed rebels and opposition coalition leader Moaz Alkhatib has said he is ready to meet Assad's representatives.

But Syrian officials say any serious talks must be on Syrian soil under state control, and have shown no readiness to discuss Assad's departure - the central demand of the opposition. For rebel fighters, who do not answer to exiled civilian opposition leaders, Assad's exit is a precondition for any negotiations.

"I continue to urge the Syrian parties to find their way to the negotiating table. The horrors of the last months and years prove beyond doubt: the military solution in Syria is leading to the dissolution of Syria," Ban said.

He also called on the U.N. Security Council, paralyzed by a standoff between the United States and European allies on one side, pushing for U.N. action against Assad, and Russia and China, who have backed Assad, to unite and address the crisis.

Moscow criticized Thursday's meeting in Rome of largely anti-Assad Western and Arab states for taking positions and steps which "directly encourage extremists" to topple the government by force.

But the Kremlin also said presidents Vladimir Putin and Barack Obama had told their foreign ministers to keep in close touch and seek new initiatives to end Syria's civil war.

U.S. Secretary of State John Kerry said on Thursday Washington would provide non-lethal aid including medical supplies and food to rebel fighters, as well as $60 million to help the civilian opposition provide services including security, education and sanitation.

The European Union said it had amended sanctions on Syria to allow the supply of armored vehicles, non-lethal military equipment and technical aid.

The steps still fell well short of what rebels are looking for - more arms, and prompted the opposition to postpone a Saturday meeting where they had been due to choose a prime minister to head the administration of rebel-held territory.

Alkhatib said he was tired of hearing Western concerns over the growing role of Islamists in the Syrian rebel ranks - one of the main obstacles to greater military support, saying it paled into insignificance alongside the prolonged civilian suffering.

"Many sides...focus (more) on the length of the rebel fighter's beard than they do on the blood of the children being killed," he said, standing next to Kerry after their meeting.

(Additional reporting by Stephanie Nebehay in Geneva and Alissa de Carbonnel in Moscow; Editing by Mark Heinrich)